Driving assembly for lawn mowers



Sept. 21, 1954 Q HAlNKE 2,689,620

: DRIVING ASSEMBLY FOR LAWN MOWERS Filed Sept. 6, 1949 2 Sheets-Sheet l Sept. 21, 1954 0. T. HAINKE 2,689,620

DRIVING ASSEMBLY FOR LAWN MOWERS Filed Sept. 6, 1949 2 Sheets-Sheet 2 ullllllllllll:

INVENTQR. 0500/ I Hamke Patented Sept. 21, 1954 UNITED STATES PATENT OFFICE DRIVING ASSEMBLY FOR. LAWN MOWERS Oscar 'r. Hainke, Enid, Okla.

Application September 6, 1949, Serial No. 114,132

4 Claims. (Cl. 180-19) 1 i This invention relates to mowing machines and particularly lawn mowers of the kind having a cutter blade underlying a horizontal frame and rotatable on a vertical axis, the primary object being to provide structure interconnecting said vertical rotatable cutter blade spindle with one or more of the supporting wheels for the mowing machine whereby to impart forward movement to the mower along the surface of the lawn to be cut. It is the most important object of the present invention to provide a lawn mower of the kind above mentioned having a train of gears operably connected to the cutter blade spindle and in turn operably connected with supporting wheels of the mower, there being manually manipulable structure connected with the assembly of parts between the supporting wheels and the train of gears operable asa clutch in stopping and starting the mower as desired and additionally, in driving the mower forwardly at differing selected speeds. 7 Another object of the present invention is to provide driving mechanism for lawn mowers having a horizontal idler shaft interposed between thevertical cutter blade spindle and the normal horizontal axis of the supporting wheels and operably interconnecting such wheels with the spindle, said idler shaft being swingable toward and from the spindle whereby to permit loosening and tightening of one or more of the drive belts, thereby presenting a clutch and further permitting driving of the mower at differing speeds.

A still further object of the present invention is to provide a driving assembly that includes a Fig. 1 is a top plan view of a driving assembly of a lawn mower having a driving assembly therefor, made in accordance with the present invention.

Fig. 2 is a side elevational view thereof.

Fig. 3 is a vertical substantially central fragmentary, cross-sectional view taken on line III- III of Fig. 1.

Fig. 4 is a fragmentary, enlarged side elevational view similar to that illustrated in Fig. 2.

Fig. 5 is a fragmentary top plan view of the outermost free end of the handle bars of the mowing machine.

Fig. 6 is an end view of such handle bars; and

Fig. 7 is a detailed, transverse, cross-sectional view taken on line VII-VII of Fig. 5.

worm formed on the cutter blade spindle and a gear in mesh therewith, there being a horizontal stub shaft on such gear, a pair of sheaves on the stub shaft as well as on the above mentioned idler shaft, which sheaves are interconnected by a pair of endless belts.

-A further object of the present invention is to provide pulleys on the idler shaft and on a pair of the supporting wheels of the mowerinterconnected' by endless belts, all to the end that when one of the belts is tightened, the idler shaft will swin to a position tightening the belts that join with the supporting wheels, there being a differential in diameters of the sheaves whereby upon tightening of one belt will drive the mower at one speed and tightening of another belt will drive the mower at another speed.

Other important objects will be made clear or become apparent as the following specification progresses, reference being had panying drawings, wherein:

to the accom It is generally well known that lawn mowers of the kind having a cutter blade mounted for rotation on a vertical axis as distinguished from the helical-type of lawn mower, have in recent years particularly become quite popular. For the most part such lawn mowers have been selfmotivating from the standpoint that the operator must push the same along as the cutter blade is driven through use of a suitable prime mover. Those experienced in the field are aware of the fact that the reason such mowers are usually moved by hand is because of the difiiculty arising in providing suitable driving means for the supporting wheels and inclusion of a satisfactory clutch that is inexpensive, easily operated and not likely to cause difliculty after short periods of use.

It is contemplated by this invention therefore, to provide a simple, inexpensive, efficient and long-lasting motivating means for such type of lawn mowers and to utilize the same prime mover as is now provided to actuate the cutter blade itself.

The lawn mower chosen for illustration includes a substantially horizontal platform broadly designated by the numeral In, that is supported by a pair of opposed wheels [2 and I4 that may or may not, as desired, have a common axle. In the instance illustrated, the axes of rotation of wheels I2 and M are horizontal and in alignment, there being stub axles l6 and 18 for wheels 12 and [4 respectively. Such axles are secured to the platform ID in any suitable manner such as by use of a bracket 20. 7

Platform I0 is additionally supported at the normally forwardmost end thereof by a single caster wheel 22 provided with a revolvable fork 24 that is in turn mounted upon a forwardly and upwardly extending bracket 26 on the forwardmost end of the platform I ll.

An elongated, horizontally disposed cutter blade 28 is disposed below the platform I and mounted on the lowermost end of a vertical spindle 30 that extends through a tubular housing 32 mounted on the platform I0.

As is clear in Fig. 3 of the drawings, housing 32 extends below and above platform I0 and is bolted rigidly thereto. Suitable bearings 34 and 36 at the uppermost and lowermost ends respectively of the housing 32, rotatably receive the spindle 36. The uppermost end of spindle 30 that projects above housing 32 carries pulley 30 that is in turn connected with a suitable prime mover broadly designated by the numeral 46 and mounted upon the uppermost face of platform It.

A twisted endless belt 42. is trained about the pulley 38 and about a pulley 44 on the drive shaft of prime mover 40. It is through such interconnection that spindle 30 and cutter blade 23 secured rigidly thereto, are rota-ted upon operation of the prime mover 40.

The improvements forming the subject matter of this invention relate to the way in which prime mover 40 is utilized to drive the two wheels I2 and I4 through the rotating. spindle 30. Such improvements include a secondary housing 46 affixed, directly to the housing 32 and communieating therewith above platform I0. Secondary housing' IB-con'tains a gear 48 mounted on a horizontal stub shaft 50 disposed forwardly of the spindle 30 and above platform Ill. The teeth of the gear 48 are constantly in mesh with a worm 52 formed on the spindle 30 within housing 32 above platform I0. The ends of the stud shaft 50 extend outwardly beyond the confines of housing 46 as is clear in Fig-l, and carry a pair of sheaves 54 and 56 respectively.

An elongated, horizontally disposed idler shaft 58 is mounted :on platform I0 in spaced relationshi to the uppermost face thereof and in substantial parallelism with stub shaft '50 through the medium o fanum'ber of upstanding brackets 60 on the platform I0. 'Each bracket '60 is in turn provided with an elongated arm 02 pivotally secured to bracket 60 at the lowermost end of arm 02- as at I54. The uppermost end of the arms 62 are each provided with a bearing '60ffor rotatably receiving the elongated idler shaft '58.

It is noted that the idler shaft 58 is located between the spindleftfl and the wheels 1'2 and I4 and terminates at its .endsin a' plane with the outermost faces of the wheels I2 and I4. The idler shaft 58 is provided with a pair of sheaves 68 and "II! in alignment with thesheaves 54 and '50 respectively on stub shaft 50. The outermost endsof the shaft 58 are also provided with a pair of pulleys "I2 and I4. Likewise, the wheels I2 and I4 are provided with pulleys I6. and I 8 respectively and secured rigidly to the outermost faces of such wheels I2 and I4.

Sheaves 54-and 08 are con'nected'by an endless belt 80 and sheaves B and T0 are joined by an endless belt 82. Likewise, endless belt '*84 is trained about pulleys i2 and '16 and an endless belt 06 .joins pulleys I4 and I8. It is contemplated that 'sheaves"54 and I0 be of substantially the same diameter and that sheaves 5'0 and 68 likewisebe of identical diameter but that sheaves 54 and I0 have diameters greater than that of the sheaves 50 and 68. Such arrangement or equivalent differential in sizes of such sheaves is provided 'to permit driving of the lawn mower at difieringspeeds as will hereinafter "be made more clear. It is preferable that 'the pulleys I2 and, be of the same diameter and that likewise pulleys "i0 and 18 be the same since irrespective of the speed of the lawn mower, both wheels I2 and I4 should be positively driven. Each of the belts 80 and '82 is provided with a tightening means that includes an L-shaped lever 88 pivotally mounted on platform In as at 90 and having a roller 92 on one end thereof in direct underlying relationship to its respective belt 80 or 82, as the case may be.

A spring .84. interconnecting the lever 88 and the platform II] on one side of the pivotal connection 90, yieldably holds the roller 92 out of operative engagement with the corresponding belt 00 or 82.. Each lever 03 has a cable 96 connected therewith and extending horizontally along, the uppermost face of platform I0 over a pulleyfia and thence upwardly and rearwardly into a corresponding handle bar section I00.

As is clear in Fig. 1 ofrthe drawing, the handle bar for the mower is provided with a pair of the elongated tubular sections I00 that'have their lowermost ends secured to brackets I02 on-the platform I0 adjacent the wheels I2 and 14. The uppermost and rearmost free ends of the sections I00 are provided with laterally and oppositely extending hand-grips I04 in the usual'manner. The cables 96 pass from the respective tubular handle bar sections IEO by means of an opening I06 provided therein :near the hand-grips I04. The hand-grips I04 are provided with triggers I03 and I09 substantially coextensive in length therewith andpivotally mounted as at H0 on'a cross plate I12 that joins the uppermost ends of the handle bar sections I00. The uppermost ends of the cables '90 are tied to the corresponding triggers "I08'and I09 intermediate theends of the lajt'terra's is clear in Fig. 5. It is seen'that the triggers 'I'08-109 are movable toward and awayfrom the hand-'grips'IM and that-when such action is imparted to the triggers=I08'I 09. the corresponding cable is moved to in' turn impart swinging movement to' the corresponding lever L88.

The trigger I09 has an elongated rod l l4 pivota'lly secured thereto and extending overlying relationship to the plate IIZ'a-nd guided by a small bearing I template I -I-2. Tha-t'end of the rod I I4 opposite to trigger4'09 terminates in-close proximity to the trigger "-I 0*8-and trigger 1 08 is in turn provided with an upstanding boss I I8 adjacent the pivotal connecticm Ito and adjacentthe rod 114. Thus, when the trigger I-08 is in the inoperative position shown in Fig. 5 of the drawings, trigger I09 can bemoved toward its corresponding hand-grip I04 as indicated innotted lines, and'the pin-H4 will clear boss H8. When trigger "I09 is -in-the dotted-line position -s'hpwn in Fig. '5, trigger I08 cannot be moved toward its hand-(grip 104 because of the boss I i-8 striking the proximal end of pinII- I. conversely when the trigger IE9 is in the position shown in full lines in Fig. 5, trigger I08 can -be"moved toward its hand-grip I 94 because of the fact' that rod IMis'clearpf the boss H0. However, after trigger I08 has been moved toward hand-grip 104, the boss I I8 will move to a position overlying the proximal endo'f rod H4 and thereby prevent movement-of trigger I09 toward'its hand-gripflll In operation, when the triggers I08 and I09 are in the inoperative'position shown in full'lines in Fig. 5, and as shown in Fig. 1, the prime'mover 40 may beplacedinop'erationtodrive the spindle 30 and its cutter blade "28 while themower re-.

I mains stationary. As soon as the "operator rite-1 I88 and moves the same toward its corresponding swinging movement asindicated by the arrow in Fig. 3 of idler shaft 58 will tension the belts 84 and 86 with respect to their corresponding pulleys I2-I6 and '|4I8 respectively.

i -As a. result" of suchtightening of the belts 84 and, the" prime mover 48 will drive wheels I2 'and l'4 at a predetermined speed as determined by the sizes of sheaves 56 and 18. Roller 82 corresponding to the trigger I88 will hold belt82 tight with respect to sheaves 56 and 18 but the, roller-82 corresponding to trigger I88, will be out of operative engagement with belt. 88.

Consequently, while stub shaft 58 continues to drive the sheave 54, no rotative action will be imparted from sheave 54 to idler shaft 58 through belt and sheave 68. In the event the operator desires to move the lawn mower at a differing speed, trigger I88 is released and trigger I88 is moved toward its hand-grip I84 in the same manner. .During such operation, the sheaves 54 and .68, as well as belt 88, operate to rotate the idler shaft 58 instead of the sheaves 56 and I8 and belt 82. Because of the differing diameter of sheave 54 with respect to sheave 56 and sheave 68 with respect to sheave 18,-two speeds are selectively possible according to the desires of the operator. In each case, the stub shaft 58 drives the idler shaft 58 and this last mentioned shaft in turn drives the two wheels I2 and I4 and it is seen that in each speed, both belts 84 and 86 cooperate to drive the corresponding wheels I2 and I4 and thereby to motivate the mower over the lawn being cut.

Through use of the rod I I4 as above described, it is impossible for the operator to bring both belts 88 and 82 into operation at the same time and because of the convenient location of triggers I88 and I88, the operator can start and stop the mower quickly and easily as desired and can change from one speed to another speed without loss of time or without any adjustments whatsoever in the component parts of the machine.

At standstill, with both handles I88 and I88 spaced away from the grips I84, as shown in Figs. 1 and 5 of the drawings, cables 86 are slack and the two pulleys 82 are pulled downwardly by the action of springs 84, whereby both belts 88 and 82 are slack as shown in Fig. 4 of the drawings. Under such conditions, if prime mover 48 is operating to drive the spindle 38 and, therefore, the cutter 28, shaft 58 will rotate idly and pulleys 54 and 56 will rotate and slide with respect to their belts 88 and 82 respectively.

If handle I88 is drawn toward the proximal grip I84 as shown by dotted lines in Fig. 5 of the drawings, exerting a pull on its corresponding cable 86, the lever 68 beneath belt 82 will move upwardly, tightening belt 82 between pulleys 56 and 18, thereby swinging the idler shaft 58 toward the housing 32 on pivots 64 and tightening the belts 84 and 86 so that both wheels I2 and I4 will be driven by shaft 58 through pulley 56, belt 82, pulley 18, shaft 58, pulleys I2 and I4, belts 84 and 66, and pulleys I6 and 18.

Because of the locking means that includes rod I I4, the handle I88 cannot at this time be simultaneously retracted toward its proximal grip I84 and, accordingly, the otherroller 82 remains biased toward the platform I8 by its spring 84, and the belt 88 remains loose. Such looseness is enhanced by the fact that theshaft 58 is swung toward the housing 32 as aforesaid by the taut condition of belt 82.

The shaft 58 does not pivot or swing on its transverse axis and, therefore, as the tightening of belt 82 tends to swing the shaft 58 toward the housing 32, both belts 84 and 86 will be tightened and pulley I2 will notswing toward the pulley I6 to tighten the belt 88. By virtue of the diifer-. ential in pulley sizes, namely, pulleys 54, 56, 68 and I8, the forward speed of the mower will de. pend upon which of thetwo belts -8882 is tightened, and is operating to motivate ground wheels I2 and I4. It must be stressed that belts 88 and 82 cannot operate simultaneously, and that one is completely slack when the otheris taut so that there is no tendency to advance the mower at two different speeds simultaneously.

It is apparent from the foregoing that an effective and efficient means of utilizing the vertical cutter blade spindle 38 in driving wheels I2 and I4 has been provided. Additionally, a clutch that is not likely to need repair or become in-v operative in any manner whatsoever in extended periods of use, has been provided. The same prime mover that is used to drive spindle 38 is utilized to motivate the mowerxover the lawn and finally, the important feature with respect to the fingertip control and its means to prevent simultaneous driving of both belts 88 and 82 are significant features of the present invention.

Many advantages will emanate from use of a lawn mower of the kind herein illustrated and described and. it is apparent that the long felt need for means to move lawn mowers of this character over the lawn, has been provided for in the structure herein disclosed.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a mobile mowing machine having a pair of spaced supporting wheels rotatable on a common horizontal axis, and a vertical cutter blade spindle; a horizontal stub shaft rotatably mounted on said machine; a train of gears operably connecting said spindle and said horizontal stub shaft; a horizontal idler shaft rotatably mounted on said machine in parallel relation to said stub shaft; a first pair of pulleys secured in spaced relation on said idler shaft; a first pair of sheaves secured in spaced relation on said idler shaft; a second pair of sheaves secured in spaced relation on said stub shaft, the diameter of at least one of said sheaves on said idler shaft being different from the diameter of the corresponding sheave on said stub shaft; a second pair of pulleys, each pulley of said second pair being operably connected to a corresponding one of said wheels; a pair of endless belts, each belt of said pair being loosely entrained about corresponding sheaves on said idler and stub shafts; a pair of endless bands, each band of said pair being entrained about corresponding pulleys on said idler shaft and said wheels; first and second means, each pivotally secured to said machine and engageable with a corresponding belt for varying the tension thereof; separate manual control structure mounted on said machine for each of said first and second means for selectively controlling either said first or second means,

idler shaft is mounted for swmging mo-yemen to ward and away from the stub .shait', whereloylwhen either. belt is trensloned :theddler shaflrwlll be swung :towardthe lsshubrshaft to loosen the other belt and tension bothhands.

3.1Infl'ImObi'1em0Wmg machine havi atv least one supporting wheelvand aprime mover; a'heri'r zontal stub shaft-rotatablymeunled on said m chine; mechanism qnerazbly conneo tingsaid prime mover. and vsaid horizontal .stubwshaft; .a horizontal idler shaftrotatazbly mounted: on said machine in;parallelzrelatloniosaid snub-shaft; a pulley secured on..-said'id1er.shaft;,a first pair of sheaves secured: in spaced relation .on said idler shaft; a second pair: of sheaveslsecured spaeed 'relation on said stub shaft, the diameter of at. least one of saidsheavesmn said idler shaft being dif fer'enltlfrom .theadiameter ,of the corresponding sheave onrsaid. stub shaft .-wheel driving means operably. connecting said. pulley with said wheel a. pair of endless "belts, leach belt of said pair being loosely ventmlnedlabout corresponding sheaves on saidridler and stub shafts; first and: second means, each pivotally secured :to said-machine. and en gageable swith 1avcorres mnding- :belt for varying the :tension thereof; separate manual control ,y on the whee a d ne SE b QQQfiZ': ahd he e; he i er. s aft-isi-mounztel o w ngin m ement; o walrdandaw y pmlhe slubshe lrwhereb either-belt. "is len on d me. dler shift wi be swlhe oward the stuhsn t to lo se t e ether beltand .the @band :tenslon si,

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